The present invention relates to coverings for architectural openings, and, more specifically, to horizontal blinds, such as Venetian blinds, designed to tilt open at double the standard pitch, while having the look of a conventional blind when tilted closed with either the room-side up or the room-side down, or to selectively tilt open or tilt closed portions of the blind.
Typically, a Venetian blind has a top head rail or other frame member, which both supports the blind and hides the mechanisms used to raise and lower or open and close the blind. The raising and lowering is done by a lift cord attached to the bottom rail (or bottom slat). The slats, which are supported from the head rail, may be allowed to tilt so as to open the blind to allow a maximum of light through the blind, or to close the blind with the room-side down (the edges of the slats which are closest to the room are facing down, which means that the other edges of the slats, the edges which are closest to the window or the wall, will be facing up), or to close the blind with the room-side up.
In some instances it is desirable to “tilt open” the blind as much as possible in order to allow more light through the blind or to allow more unhindered viewing area. In this instance, it is possible to achieve this using standard width slats wherein adjacent pairs of slats move together to stack against each other when tilted open, resulting in a “double pitch” arrangement. In this double pitch arrangement, the open area between adjacent pairs of slats is essentially twice the open area that would be achieved if the slats were spaced apart equally in the normal arrangement, thus the “double pitch” designation.
Tilting the blind closed may be done for the purpose of blocking out light, or for obtaining privacy, or both. In order to obtain the optimum performance from the blind, it may be desirable to open one portion of the blind while closing another portion of the blind. For instance, it may be desirable, in an office setting, to tilt closed the lower portion of the blind in order to block the glare of sunlight on a computer screen, or to provide privacy so someone standing outside the window cannot stare through the window and see what is on going on inside the room. However, at the same time, it may be desirable to have the upper portion of the blind tilted open to allow some natural light and/or ventilation into the room. Another instance of an application for such a “split” blind design may be in a home where the floor of the house is at a higher elevation than the ground outside. A person standing in the house could freely see outside, but a person from the outside could not effectively see inside except for the uppermost reaches as allowed by the open section of the blind.
In addition to the issue of privacy and glare elimination, the light control feature of the split blind design (also referred to as selective tilt design) is also beneficial in that it minimizes the ultraviolet light deterioration resulting from sunlight impacting on interior furnishings, rugs, hardwood floors, etc. while still maintaining indirect lighting from the outside as well as a clear view of the outside. This is particularly practical and applicable in buildings with a roof overhang over the window area or where the windows are recessed into the wall, creating an overhang.
In still other instances, it is desirable to tilt a slat closed in one direction (say, room-side up) while the slats immediately adjacent this slat are closed in the other direction (room-side down). This results in an aesthetically-pleasing “pleated look” (also sometimes referred to as a Tiffany look) of the blind when in the closed position.